Search found 108 matches
- 6 years ago
- Forum: Syntax
- Topic: How can I force GAMS to compile this code in its written order?
- Replies: 4
- Views: 4205
Re: How can I force GAMS to compile this code in its written order?
In fact, I want the first display Z.l shows the value "a" and the second display Z.l shows the value of "b". To make it more clear from my post and Gideon's: you can't . I think you missed my line opening the code example: Therefore, your code is actually executed in this way by...
- 6 years ago
- Forum: Syntax
- Topic: dynamic growth syntax without max/min solve statement
- Replies: 1
- Views: 2076
- 6 years ago
- Forum: Syntax
- Topic: How can I force GAMS to compile this code in its written order?
- Replies: 4
- Views: 4205
Re: How can I force GAMS to compile this code in its written order?
GAMS makes two different "passes" of the file when "preparing" the model, they are usually referred to as "compile" and "execution" phase or time. "compile" comes first, then "execution". As you can see in https://www.gams.com/latest/docs/U...
- 6 years ago
- Forum: Modeling
- Topic: Individual LP v.s. Integrated LP in GAMS
- Replies: 6
- Views: 5229
Re: Individual LP v.s. Integrated LP in GAMS
The issue may not be so simple, look at this post by the great Michael Bussieck: https://forum.gamsworld.org/viewtopic.php?t=10080#p23097 But, as far as I understand, no, "Execution" in this context means GAMS execution, not the solver. From the page I linked: This is the time required for...
- 6 years ago
- Forum: Modeling
- Topic: Individual LP v.s. Integrated LP in GAMS
- Replies: 6
- Views: 5229
Re: Individual LP v.s. Integrated LP in GAMS
Hi, why did you discard your first hypothesis ? If you look at the .lst file, you can see that the time is in fact spent in GAMS "execution" and "generation", rather than in the actual "solve" time (which is detailed as "resource use" of each solve. Check: htt...
- 6 years ago
- Forum: Syntax
- Topic: Errors 654, 409, 148,125
- Replies: 2
- Views: 3154
Re: Errors 654, 409, 148,125
First. Read https://www.gams.com/products/simple-example/ , you've got all your sum() operators syntax wrong. (this is your 148) Second. In equation cograde, it is written for every " i ". So, when you mean sum( (i,j), ... ) do you really mean " i " again, or do you mean sum(j,.....
- 6 years ago
- Forum: Syntax
- Topic: index set control
- Replies: 3
- Views: 3455
Re: index set control
I don't know VRP models and sincerely I can't understand from your description what this constraint is supposed to achieve. Do you mean: "If a vehicle arrives at a point p, it must also leave it" ? If so, this can be written as: arrAndDep(k,p).. sum(i$(not sameas(i,p)),x(i,p,k)) =e= sum(i$...
- 6 years ago
- Forum: Syntax
- Topic: index set control
- Replies: 3
- Views: 3455
Re: index set control
Hmm, this line is incorrect:
arrive(k).. sum((i,pp),x(i,pp,k)) - sum((p,j)$(p.val=pp.val),x(p,j,k))=e=0;
You don't have "control" of set pp at that point, more informally, which element of pp do you mean to appear ?
What is the constraint supposed to achieve ?
arrive(k).. sum((i,pp),x(i,pp,k)) - sum((p,j)$(p.val=pp.val),x(p,j,k))=e=0;
You don't have "control" of set pp at that point, more informally, which element of pp do you mean to appear ?
What is the constraint supposed to achieve ?
- 6 years ago
- Forum: Syntax
- Topic: Getting error (rPower: FUNC DOMAIN: x**y, x < 0)
- Replies: 4
- Views: 5283
Re: Getting error (rPower: FUNC DOMAIN: x**y, x < 0)
What do you think of this intrinsic function ?
signPower(x,Y)
It will get you the value of the real branch when it exists (which is your case).
signPower(x,Y)
It will get you the value of the real branch when it exists (which is your case).
- 6 years ago
- Forum: Modeling
- Topic: Stuck at some tolerance value
- Replies: 1
- Views: 2161
Re: Stuck at some tolerance value
Is this a MILP model ? Which solver are you using ?